In accordance with modern requirements with respect to the sterility of filling plants, in particular aseptic treatment plants, it is necessary for the containers to be provided as far as possible in a sterile environment during the entire treatment process. It is therefore necessary not only to keep the interior of the containers or the preforms sterile or germ-free but likewise to keep the exterior of the pre-forms or the containers sterile or germ-free, so that a transfer of bacteria, viruses, germs or the like present on the outside of the containers cannot take place in the region of the interior of the containers or the pre-forms and so contact of the filled material with bacteria, viruses, germs and/or the like is prevented.
It may be desirable therefore to ensure that, even during the shaping of a pre-form into a container, as few germs, bacteria, viruses or the like as possible can penetrate into the interior or into the region of the opening of a container during the shaping of a plastics material pre-form into a container.